227 



positiou of tbe uephridiopores iu the coraraon eartliworms. It was 

 this fact tliat made me believe the casual observation to be 

 uovel , but I have to thank iny frieiul Dr. R. Horst for having 

 called my atteutiou, not only to the fact that ah'eady Hering and 

 Claparède havo raentioned the occurence of cousiderable diver- 

 gence in the positiou of the uephridiopores, but that this diver- 

 geuce was specially treated as late as 1887 by Dr. A. Borelli in 

 a short italiau contributiou to the subject, which appeared iu 

 the »Bollet{no dei Musei di Zoologia ed Anatomia Comparata di 

 Torino'^ vol. IT, u". 27. 



Borelli gives a comparative table of specimens of the following 

 species in which he has recorded the positiou of the uephridiopores 

 iu a very cousiderable number of segmeuts : Lumbricus rubellus 

 HofiFm, L. purpureus Eisen, L, herculeus (Sav.), AUolobophora 

 turgida Eisen , AUolobophora chlorotica (Sav.), AUolobophora trans- 

 padana Rosa, A complanata (Dugès). 



Borelli coucludes from this tabular arrangement that : 



»the nephridiopores of these European earthworms are uot all 

 »fouud just above the second seta but eau occupy in the same 

 »iudividual specimen three different positious , i. e. just above the 

 » second seta, just above the fourth seta or fiually iu the space 

 »between the fourth seta and the dorsal pore." 



And further : 



»in correspouding segmeuts of individuals of the same species 

 »the nephridropores can be fouud iu either of the three positions 

 »indicated and iu the same specimen these positions foUow and 

 »alternate without auy regular order, nor do they present any 

 »symmetry in the same segment." 



These couclusious fully coincidiug with my owu observations , 

 that were made before I was acquiuted with Borelli's paper, I 

 would certainly not have published this coufirmation , wliere it 

 not that Borelli does not give auy figures illustrating the facts 

 here recorded '). 



1) I have no doubt that Prof. Busk's drawing which was reproduced in a woodcut 

 in Uay Lankester's article on the earthworra (Q,uart. journ. 1865, p. 102) would have 



